Intermittent inductive train-control system



ocr. 18, 1927.

l 1,645,555` W. R. MCCATHRAN INTERMITTx-:NT INDUCTIVE TRAIN CONTROL SYSTEM Original Filed Qct. 24, 1925 2 Sheets-Sheet 2 @www Wham/vw RJ/(c CaIMam @aways Patented Oct. 18, 1927.

UNITED STATES entreraiv orricn.

`-WILLIAMREED MCCATHRAN, on WASHINGTON, Dls'rnicror COLUMBIA.

INTERMXTTENT INDUCTIVE TRAINTCGNTROL SYSTEM.

Application filed October 24,1923,Sera1 No. 670,547. Renewed March 12, 192'?.

This invention relates to improvements in block signalling and train control sys tenis. U

' One of the objects-of this invention is to provide a train device which operates only when oppositeV a track device and preserves the setting then given until it passes over a succeeding device upon the track.,

Another object is to provide a track device which is simple, has no moving parts save those controlled by the track relay and the semaphore, and is adapted for use with g traffic moving in either or both directions;

Another object is to provide means for permissive control in the train circuit, whereby the speed of the 'train may be reduced by the engineer in vaccordance With the signal indication at 'theisemaphore, but if not so reduced, a positive brake applica* tion will be given.

Another object. 1s to make the-train andy track apparatus electrically independent but magnetically cooperative when the rain elements are in proper relation to the track elements. l g

Another object is `to provide a trainsystem such that a positive act by the engineer is required to enable the train to enter a block ivhen the block is in the danger or caution condition. Another object is to dispose the train elements of such a system sov that a failure of any part-Will cause an operation ofv said elements similarly to the danger position or condition of the track semaphore ap# paratus. i

Another object is to incorporate in thet-rain circuits a speed-controlling means to limit the permissive train peedsy corresponding to the condition of the block about to be entered. y

A further object is to render such systems automatic in operation upon the occurrence of foreseen conditions and -to cause a danger7 indication and operation in the event of lack of battery power, breakage of a rail or of the apparatus, or other unforeseen conditions.

)Vith these and other objects in View will appear from the following` specification and claims, one exemplitication of execu-l tion of the invention is shown on-the accompanying drawings, in which: Figt l is a diagrammatic presentation of the train and track'circuits in anormal or clear position. 'Y

governor device and train way: induction coils on them have currentsV induced therein by the passage of the train elements'thereover. These track coils are connected together ras kdescribed hereinafter. The train. elements are magnetized by a current from a suitable alternatonand are connected with a speed-governor, air release kvalve in the brake-pipaa contr-ol relay, and

al bank of signal lamps. f

-The fundamental indications are` danger (red lamp with emergency stop or very low speed), caution (yellow lamp or me-:

dium speed), and safe (green lamp and a predetermined maximum speed).

)When the train enters a block, they train elements pass over the ktrack elements of that block. If the block ahead is clear, 'the track elements are conneoted'in series, so

i that the `one train element induces la currentfin the corresponding track element coil,

this induced track current magnetizes the Y other trackelement, which in turn induces` thefcontrolling current in the second train element to set or Vmaintain the train apparatus at safe f If the block ahead is in a non-clear condition but the train may pass through it ata slower speed, the track semaphore indicates "cautioin and a 'switch on the semaphore arm reverses the connectionsof the tvvo track elements. As vthe train passes over them,the induced track currentpasses as before, butinduces a current in the reverse direction in the train element coil, which causes the train apparatus to indicate and operate at cautionv In the event of broken rails, a train immediately ahead, failure of track battery, or other trouble, the two track elements are not connected together, andinoA current is induced in the second track element. The train/apparatus then falls to a. neutral position and a vdanger indication and operation is effected. n'

After this summary, the invention will now be described in relation to the draw turbine, or belted to the engine wheels. Y The wires 41, 41 lead to the coil 42 of an alternating current electromagnctforming a dynamometric relay B. This relay has a plurality `of contact blades 1, 2, '3, 4 insulated electrically from each other but connected mechanically for simultaneous operation to be brought intov any of the three positions R, C, and L, corresponding respectively to the right, center, and left positions in the drawing, in which the contact blade 1 makes contact with points 13, 14, or 15, and the other blades make similar contact with their respective corresponding points.

Upon the locomotive is likewise provided a governor C driven from a bogey wheel or other appropriate rotating member so as to be rotated at a speed corresponding to the train speed. This governor is shown in Fig. 2 as provided with al circuit closingbar c engaging with selective sets of a number of contacts, depending upon the train speed. On the drawing, the centrifugal governor is provided with three suchcontacts at H,`M, and L, corresponding to high, medium, and low train speeds. The contact plate 7L opposite H and Mis connectedv by a wire 43 to an alternating current electromagnet D. The other terminal of electromagnet D is connected by Wires 44, 45 and 41 to one side of generator A. Thefelectromagnet D has a plunger 150 formed with two opposing valve seats, a large one 151 and a small one 152, designed for alternate respective lodging on seats 153 and 154 in the walls between the main bore lor cylinder chamber 155 vand the side chambers 156 and 157 of an electromagnv netic air valve. The actuation of the plunger 150 by spring 151 upon de-energization ofthe solenoid D permits the compressed air in thebranch pipe 158 connected to the train pipe to pass the valve 151 and enter the main bore chamber or `cylinder 155; iii the latter it forces piston 159 upwards and permits the compressed air to escape from train pipe 160 through the valve 161 -iiito` the pipe 162. This servomotor type of control is preferred, but in small installations, the compressed air in pipe 158 maybe allowed to escape directly to dthe atmosphere, to accomplish the same en The contact plate Z opposite contact L is connected by wires 46 and 47 to a push button K.mounted at an easily accessible point of the locomotive cab. From push button K, a wire 48 leads to one terminal of the resetting magnet RM, and a wire 49 leads to one stationary contact 50 of the circuit maker and breaker 25. rlwo moving contacts 51 and 52 of this circuit breaker and maker 25 are mechanically connected for simultaiieous opeiation by the electromagnet RM, and are both connected electrically by wire '53 to wire 46. The other stationary contact 52 of the circuit breaker 25 is connected by a wire 49 to wire 43 and thus to one terminal of electromagnet D.

Returning to the groups of contacts of relay B, the right-hand contact 13 opposite the ymoving blade 1 which receivesv current from wire 40 is connected by a wire 56 to a green lamp G, the center Contact 14 by a wire 57 to a red lamp R, and the lefthand contact 15 by a wire 58 to a yellow lamp Y. The othery terminals of the lamps are connected by the return wire 45 to the generator A. The lamps are located in an easily visible location in the locomotive cab. Y

The second moving blade 2 likewise receives current from wire 40. Its righthand contact 16 is connected by a wire 59 to the Contact plate H of the governor C; its center contact 17 by a wire 6() to the plate L, and its left hand Contact 18 by a wire 61 to the plate M.

The third moving blade 3 is connected by v a wire 64 to the coil 65 of a train element F.

Its righthand contact 19 is connected bya wire 62 to the left hand contact 24 of the fourth group and to the return wire 40 leading to the generator A; the center contact 2O by a wire 63 to the center contact 23 of the fourth group; and the left-hand contact 21 by a wire 66 to the supply wire 40, and by wire 67 tothe right-hand contact 22 of the fourth group.

The fourth moving blade 4 is connected by a wire 68 to the-other terminal of the train `magnet F. The stationary contacts 22 and 24 of this moving blade 4 are connected as noted above. Y

The outer four contacts of the third and fourth groups, with their moving blades, therefore function as a reversing switch, i. e.l when the moving blades are all in the righthand position, the circuit from alternator A passes by wires 40 and 67 to contact 22, moving blade A4, wire 68, winding of magnetF, wire 64, moving blade 3, contact 19,- wires 62 and 40, back to the alternator; and when the blades are in the left-hand posiA tion, the circuit is formed from alternator A by wires 40 and 66`to contact 21, moving blade 3, wire 64, winding 65 of magnet F, wire 68, blade 4, contact 24, wires 62 and 40, back'to the alternator A. f

The train magnets E and F are disposed llO 111 on the track element Z and the primary coil 65- of the train magnet F cause 'the flux to travel in the same direction, i. e., from 8V towards 7, the coil 35 will be energized with the same polarity and phase relation as under normal conditions while proceed ing between block ends, and the relay B will be retained in its normal or right-hand position.

It the signal S be moved to the caution7 position, the pole-changer N is moved to the right-liand position of Fig. 1, and the arm 11S of the switch P to the position on 120. The pole-changer has now reversed the relative direction of the current through the coil 111, in the manner customary for such pole-changers, and therewith the direction of the flux in the core of Z, so that the flux from 131 towards 130 opposes the ilus. from towards 6, in the primary coil 65 of the train element F. By suitably dimensioning the parts so that the flux from Z is much stronger than that already existing in F, a reversal occurs of the current induced in coil 35. The current in the coil 34 now countera-cts the influence of the coil 42 since it is reversed in phase relation andthe moving blades of relay B are drawn into the opposite or left-hand position. Current now flows trom generator A. by wire 40 as follows: moving blade 1, contact 15, wire 58, yellow lamp Y, wire 45 and 41, back to the generator A; also by moving blade 2, contact 18, wire 61, contact M, bridge c and if Vthe train speed be not above that for which the bridge arm c of the governor C i is adjusted, i. e. a medium speed-by this bridge arm to contactk 71 wire 43, magnet D, wires 44, 45, 41, back to the generator (hence it the train speed is not above certain medium speed, the air valve is held closed, but it greater the valves are opened and the brakes applied) also by wire 66, contact 21, moving blade 3, wire 64, coil of train element F, wire 68, moving blade 4, contact 24, wires 62 and v40, back to the generator A, thus energizing the train element in the. opposite direction and causing the current induced in coil 35 to retain the relay B in the left-hand or caution position.

lVhen a train is on the right-hand block, the signal S is in the danger or stop position, the signal switch P is on point 121, and its circuit by wire 117, switch arm 116, wire 113, relay'blade 107, contact 132, wire 109,` winding 111, wire 110, contact 133, relay blade 108, wire 115, contact 114, switch arm 116, wire 125, winding 124, wire 123, back to contacts 120, 119 and bridge plate 122 is open. The train wheels and axles short-circuit the rails 101, 101', and (the track relay TR no longer receives battery current, so that its armature falls and opens the contacts at 132 and 133. The coil 124 of the Vauxiliary track element X and coil 111 of track element Z are opencircuited. This likewise is the case upon failure or breakage of the connecting rails or wires. It the train on the lett hand block passes over the track elements when they are in this condition, no current is supplied to the coil ot the track element Z, but its core furnishesy a magnetic path of vless reluctance than the air-gap 69 of the train magnet element F,

so that the iiux travels by 56-810- 131`-1BO-97-5, thus diminishing' or annihilating the flux from 8 to 7, and prevent ing current being inducedV in the coil 35. The coil 34 no longer receives current, andA the relay B falls to central or danger position. Current now flows from the' generator A by wire 40 as follows: moving blade 1, Contact 14, wire 57, red light R, wires 45 and 41, back to the generator A; also by'moving blade 2, contact 17, wire 60,' contact L,-'and if the train speed is not greater than the predetermined low speed for which the bridge arm c is adjusted-by bridge arm c of the governor C, contact Z, wire 46, and 47, to push botton K and when the latter is closed by the engineer, by wire 48, magnet RM, wires 44, 45, and 41, back to thegenerator A, thus energizing the resetting magnet RM and closing the contacts 50-51 and 52-52 to short-circuit the push button K and keepmagnet RM energized, and to `keep the airvalve retaining magnet D energized. The engineer in pressing push button K is reminded that he is entering a danger zone; which is also kept in his attention by the red lamp. A' circuit is also formed from coil G5 by wire 68, moving blade 4, contact 23, wire 63, contact 20, moving blade 3, wire G4, back to coil 65, thus short-circuiting this coil. The train may now proceed only at a low speed until a set oi' track elements corresponding to those at X and Z are encountered in a Cclear7 or caution position,

so that coil 111 corresponding to coil 35 is energized, and the relay B is moved to one of its end positions. lThe operation upon such an occurrence is Vthat which has been describedv above.

If the train be travelling with the relay in the clear position, and the safe speed `for which the apparatus has been set is exceeded, the bridge arm H will be raised awayfrc-m its contacts and open the circuit of the air valve retaining magnet D, so that i the air brakes will be applied.

The engineer, in using the push-button K andobserving the signal lamps is continuously advised of the exact condition of the block head; and if a danger actuation be delivered, his locomotive is unable to enter the block except after he had 'done the positive act of depressing K.

I claim:

1. In a train control system, the combination with the track rails, track battery, track relay, a normally deenergized track magnet adapted to be energized by a train magnet, and a second normally deenergized ytrack magnet adapted to be energized by the current induced in a coil of said lirst track magnet flowing through the contacts of said track relay in closed position, of a constantly energized train magnet adapted to cooperate with said rst track magnet, a second normally weakly energized train magnet adapted to be reversely energized by induc tion from said second track magnet, and a train-controlled relay actuated by current induced in a coil of said second train magnet.

2. A train control system comprising two track elements, a track relay and track battery adapted in the safe condition to close a series circuit including said track elements, a iirst and a second train element to respectively induce current in and receive current from said track elements in the safe condition, means to energize the coil of said lirst train element, and weakly energize the primary coil of said second train element, a secondary coil on said second train element adapted to have current induced therein by the weak energization, a. train-controlling relay held in the safe condition by the current induced in said secondary coil, said train and track elements adapted to cooperate upon open-circuiting of the track relay contacts to prevent induction in said secondary coil and to bring said train controlling relay to a danger condition, and means associated with said relay to open-circuit said primary coil so long as said train relay y is in the danger condition.

3. A train control system comprising a normally weakly energized train element, track means to assist the energization of said element, a train-controlling relay adapted to be brought to a safe condition upon such assistance, and contacts for said relay and means associated therewith to retain said relay in the safe and danger conditions determinedl at passage of the train over a track means.

4t. A train control system comprising a normally energized first train element, a normally weakly energized second train element, a track element adapted to be ener gized by induction :trom said first train element and including a coil to have current induced therein by said energization, a semaphore and reversing switch, a second track element adapted'to be energized by the current from the coil of said irst track element ina direction reverse to that of the weak energization in Athe safe condition oit said second train element when said semaphore and switch are in a caution condition, a train controlling relay including a position-retaining means and actuated by current induced in a secondary coil of said secondtrain element, said second track element adapted to counteract the weak normal energization and establish a reverse energization in said second train element, whereby said train controlling relay is brought by the' reversed current induced in the secondary coil of the second train element into the caution con` i dition. a

In testimony whereof he aiixes his signa ture.

WILLIAM REED MGCATHRAN. 

